simplest way to add an authentication page to windows universal app

From @JON_D84via Twitter

So what's the simplest way to add an authentication page to a windows universal app? With@Azure mobile services, hardly any Documentation!

@bugail responded with this link: azure.microsoft.com/en-us/documentation/articles/mobile-services-dotnet-backend-windows-universal-dotnet-get-started-users/ …

To which @JON_D84 responded: @bugail@Azure I've tried that the win 8 project structure is different to a UWP app. And also doesn't explain redirect when authenticated